Secondary leukaemias. Clinical and cytobiological aspects.

Patients treated with radiation and cytotoxic agents for a variety of neoplastic conditions develop with increased frequency a secondary leukaemia, usually a form of acute myeloblastic leukaemia. The authors illustrate and discuss the various morphological and cytobiological which characterize the "preleukaemic phase", and which comprise myelodysplastic alterations, cytochemical abnormalities, concerning the presence of glycogen and free iron in the red cell series, as well as a number of changes in enzymatic activities in the myeloid series, cytokinetic changes, indicative of accumulation of cells in G0 and G1, cytogenetic non-random abnormalities, involving specific chromosomes, and finally in vitro cultures which show a reduction in colony formation. The authors underline the differences between primary and secondary preleukaemic myelodysplastic states, consisting in the presence in the latter of frequent hypocellularity, fibrosis and almost invariability a clear involvement of multiple cell lines.